title: [Synthetic studies on natural products with aromatic nitrogen heterocycles based on development of the methods for the formation of aryl carbon-nitrogen bond].
abstract: Total syntheses of yatakemycin, PDE-II, dictyodendrins, and heptaphylline are described. This article focuses on the formation of aryl carbon-nitrogen bonds by two methods: first by an aromatic amination reaction using a combination of CuI and CsOAc, and then by a benzyne-mediated one-pot cyclization-functionalization sequence. The aryl amination reaction shows a high functional group compatibility and applicability for highly hindered substrates. The utility of this reaction has been fully demonstrated through a total synthesis of yatakemycin, which features the regioselective ring opening of (S)-epichlorohydrin with 2,6-dibromophenyllithium species and the efficient deprotection of benzyl groups of aryl benzyl ether with BCl3 in the presence of pentamethylbenzene. The copper-mediated aryl amination reaction was applied to a one-pot double aryl amination for facile access to the highly substituted pyrroloindole skeleton, which led to a concise total synthesis of PDE-II. A highly efficient total synthesis of dictyodendrins A-E was accomplished by the development of a novel benzyne-mediated one-pot indoline formation/cross-coupling sequence for the construction of a highly substituted key indoline intermediate. Peripheral substituents were introduced onto this intermediate in a modular fashion to complete the total synthesis of dictyodendrins A-E. The utility of the one-pot benzyne-mediated cyclization-functionalization reaction was demonstrated by the total synthesis of carbazole alkaloid, heptaphylline.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tohoku University.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Okano
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis*; D000586:Amination; D001555:Benzene Derivatives; D001688:Biological Products / Q000138:chemical synthesis*; D002227:Carbazoles / Q000138:chemical synthesis*; D002244:Carbon / Q000737:chemistry*; D002625:Chemistry, Organic / Q000379:methods*; D003300:Copper; D054678:Cyclic Nucleotide Phosphodiesterases, Type 2 / Q000138:chemical synthesis*; D003500:Cyclization; D000080890:Duocarmycins; D007211:Indoles / Q000138:chemical synthesis*; D009584:Nitrogen / Q000737:chemistry*; D055601:Organic Chemistry Phenomena; D011758:Pyrroles / Q000138:chemical synthesis*
chemical_list: D000470:Alkaloids; D001555:Benzene Derivatives; D001688:Biological Products; D002227:Carbazoles; D000080890:Duocarmycins; D007211:Indoles; D011758:Pyrroles; C524146:benzyne; C557424:heptaphylline; C474180:yatakemycin; C041514:carbazole; C057812:indoline; C039063:pentamethylbenzene; D002244:Carbon; D003300:Copper; D054678:Cyclic Nucleotide Phosphodiesterases, Type 2; D009584:Nitrogen